1. Field of the Invention
The present invention relates generally to wireless communication. More particularly the present invention relates to wireless communication using radio frequency signals.
2. Related Art
Wireless communications systems, and in particular multiple-input multiple-output (MIMO) systems, have achieved remarkable capacity gains in the last decade. While theoretical performance limits can be calculated for many wireless communications scenarios, often system implementations fail to achieve more than a small fraction of the theoretically available performance. Much effort has been exerted in developing complex signal processing algorithms which, in some cases, provide only a few decibel of improvement.
MIMO systems can provide large improvements in capacity relative to single-input single-output (SISO) systems. In theory, the available capacity of a radio channel can increase linearly with the number of antennas at either the transmitter or receiver. Unfortunately, complex signal processing is generally required in order to obtain the increased throughput. The size and cost impact of adding antennas and cost of increased signal processing has slowed the adoption of MIMO technology. The impact of additional antennas and processing has caused some to view MIMO as impractical for mobile communications systems.
Simple techniques for providing capacity improvement in wireless communications are therefore highly sought after.